Glazing apparatus



H. v. scHwElTzER GLAZING APPARATUS Filed April 6, 1940 3 Sheets-Sheet 3 mvENToR v wmen V' Scl/wf/rzfk ATTORNEYS Patented Feb 1o, 194s GLAzxNe APPARATUS Howard V. Schweitzer, Shaker Heights, Ohio Application Api-ii' s, 1940, serial Nn. 328.272

. 13 claims. 1

' This invention relates to apparatus for glazing.

t and, more particularly, to apparatus for spraying glaze upon ceramic ware of substantially all shapes and sizes and for' obtaining a smooth and uniform coating of glaze on all surfaces of such ware.

Heretofore the universal practise in applying glaze to ceramic ware was to dlp the unglazed Ware manually into a vat of liquid glaze and by carefully removing the ware from the vat so that excess -glaze did not accumulate on the ware, a smooth coating of glaze was obtained. This manual operation was not only slow and expensive but required considerable skill on the part ofthe dipper." Ware not only is substantially unlimited as to size and shape, but vitreous and semi-vitreous ware will vary in porosity depending upon its location in the kiln wh'en fired. Considerable skill must be exercised by the dipper in selecting a thin, medium, or thick glaze to be used so that a thin, wet glaze, for example. will not run or curtain" before it is dry and absorbed by a. piece of ware of low porosity.

It is an object ofv this invention to provide apparatus for applying glaze mechanically, rather than manually. Another object of this invention is to provide apparatus by which a smooth, even coat of glaze may be applied to ware of substantially any size or shape and of varying degrees of porosity. It is a still further object of this invention to provide apparatus for applying glaze so that the glaze will not curtain on the ware after it is applied.

Other and fuurther objects `and advantages of this apparatus will appear from the following specification, claims, and drawings in which:

Fig 1 is a plan view of a machine made according to this invention with portions broken away to show the table drive and spindle drive;

Fig. 2 is a sectional view taken along the line 2 2 of Fig. 1;

Fig. 3 is a front elevation of the machine;

Fig. 4 is a diagrammatic view illustrating the relationship of the lseveral elements in the glazing apparatus and the vglaze circulating system:

Fig. 5 is a detail view of the gun shaft connections taken along the line 5-5 of Fig. 3; and

Fig. 6 is a detail view of the gun oscillating drive taken from the line 6 6 of Fig. 1.

In the drawings, in which like reference characters refer to like parts, I refers to a large conical table having a smooth, sheet metal surface II supported by a plurality of spokes I2 secured to a central post I3 which revolves upon suitable thrust bearings I4 mounted in the base frame I5. The sheet metal surface I I overhangs the periphery of the table I0 to form a depending eave I8 which revolves in a fixed circular trough Il. The trough I1 is preferably supported from the base frame I or from thel floor upon which the ma- (Cl. (i1-45) chines rests so that the trough is provided with a fall from the back to the front of the machine.

Depending from the table I0 is a large V-belt table sheave 2i which carries one or more V-belts 22 driven by the pulley 23 of a Reeves speed reducer 24 which. in turn, yis driven by an electric motor 25,- Suitable slack take-up means (not shown) are provided to insure an effective drive from' the motor 25 to the Reeves 24 and from the pulley 23 to the table sheave 2|.

A plurality of vertical spindles 30 are rotatably mounted in suitable bearings 3i adjacent the l periphery of the table I0 and substantially equidistant from each other. Each spindle 30 carries a small V-belt pulley 32 on its lower end below the table I0, and above the table it is equipped with a removable ware holder 33 provided, preferably, with three wire prongs. A cup 34 is carried on the portion of the spindle 30 which extends above the table to protect the bearing SI from glaze. .I

A spindle drive is located across the front of the machine and comprises, at oneend, a motor' 40 and a Reeves speed reducer unit 4I which carries a main drive pulley 42 adapted to engage the flat back of a V-belt. the drive is a main idler pulley 43, the drive pulley 42 and idler pulley 43 being so located that a line through their centers would be a chord subtending an arc of the spindle orbit across the front of the machine. Each spindle pulley 32, as it passes across the front of the machine, therefore, engages the V-face of a V- belt 44 driven by the main drive pulley 42 and supported by the main idler pulley 43. Because the path of the drive portion of the V-belt is arcuate, the returnportion of the V-belt is spaced therefrom by the auxiliary idler pulleys 45. The V-beltl 44 thus is employed to impart planetary motion to the spindles 30 across the front of the machine. The rotation of the spindles is usually in a direction opposite to' the direction of revolution of the table I0, and. if the table Ill revolves in a clockwise direction, as shown, the V-belt 44 is usually driven in a counter-'clockwise direction to increase the speed of rotation of the spindles over that which would be obtained if the V-belt 44 would be held stationary. Since the speed and direction of rotation of the drive pulley 42 is variable, the speed of rotation of the spindles 30 is variable over a wide range and may be decreased from a high lcounter-clockwise speed to a peripherial speed, i. e., the spindle rotation speed obtained when the V-belt 44 is stationary, and, by reversing the motor 40, the spindle speed may be further reduced until there is no spindle rotation at all, i. e., when the speed and direction of travel of the V-belt 44 is equal to the peripherial speed of the tableV I0.

At the other end of A spray booth is located over the front of the table I and is provided with a floor 5| converging upwardly and rearwardly toward an outlet 52 which may be connected to a suitable exhaust system (not shown). The outer margin of the floor I is conical so that the edge thereof is closely adjacent the conical surface Il of the table l0 inside the spindles 30.' Located within the booth 50 adjacent the outlet 52 are a plurality of -spray baille plates 53, for which an inspection and wash-down `door 54a is provided in the top of the booth. 'I'he front of the booth is curved to be substantially concentric with the table I0 and is located outwardly beyond the periphery ofthe table l0, so that v the spindles travel within the booth 50. The

- which are hinged well back of the orbit of the spindles 30 and are slanted ata steep angle forwardly toward the front wall of the booth so that excess glaze spray which may accumulate on the doors 51 and 58 will not'. drip down on ware carried by the spindles but will run down the underside of the doors to the front wall of the booth. The bottom of the booth comprises a deep arcuatetrough 60, the bottom of which slopes forwardly and toward the center of the booth to a drain 59. The ends of the trough 60 are connected to the table trough l1 so that glaze caught in the table trough l1 will drain into the booth trough 60 and the depending eave I5 which runs in the trough I1 overhangs the back wall of the trough 60. The two side walls of the booth 55 are closed, except for the necessary openings (not shown) for the table I0, spindles 30 and the ware carried thereby which must pass through the side walls of the booth.

A lower gun shaft 62, suitably supported in bearings secured to the frame of the booth 50, extends across the lower gun opening 54; an upper gun shaft 63, similarly supported, extends across the upper gun opening 55. -A plurality of lower glaze spray guns B4 (five in the embodi-F ment shown in the drawings) are carried by the lower gun shaft 62; similarly, a plurality of upper spray guns 55 are carried by upper gun shaft 63. As shown in Fig. 4 of the drawings, each glaze spray gun is mounted on a gun shaft by means of a holder comprising a rod 66 slidably mounted in a collar B1 attached to the gun shaft, each gun being pivotally secured on a bent stud end of the rod 86. Thus, it is apparent that each spray gun may be universally adjusted as to the angle at which its jet is directed and also as to its distance from the ware which is to be sprayed. Also, as shown by Figs. 4 and 1, the spray guns are preferably designed to spray glaze in thin fiat fans of spray, i. e., the glaze is sprayed so that it diverges laterally, but the depth of the spray is thin at the jets and remains substantially constant throughout the length of the spray. Also, the guns are held on the gun shafts so that in their normal position thejets of spray are directed toward the center of the ware supported by the spindles and so that thespray tends to diverge laterally.

The number of guns mounted on each shaft may be varied, of course', the number of guns on each shaft being spaced from each other so that the sprays from adjacent guns do not interfere. is also apparent from the drawings, the lower gun shaft 62 is located well below the ware carried by thespindles and the upper gun shaft 53 is located above the ware. Thus, the lower guns 64 are directed upwardly and are adapted to spray the lower and outer surfaces of ware thethin fans of spray will coat all portions of the ware carried by the spindles. A motor 15 for oscillating the gun shafts is vlocated adjacent an end of the booth and is preferably mounted thereon. The motor'10 is provided with a crank 14. 'I'he knuckle member 14 is slidably mounted on a crank arm 15 which is fixed at right angles to one end ofthe lower gun shaft 62. The crank arm 15 is threaded throughout its length so that the position of the knuckle 14 thereon may be adjusted and secured by the locking nuts 15. Thus the throw of the crank arm 15 may be adjusted at will and the angle of oscillation of the gun shaft 82 may be varied to suit the size of the ware which the lower guns 54 must spray. The forked member 13, knuckle member 14, crank arm 15, and locking nuts 16 will be referred to hereafter as the crank and knuckle assembly 11.

To transfer the oscillating motion of the lower gun shaft 82 to the upper gun shaft.'a crank and knuckle assembly 60, similar to the crank and knuckle assembly 11, is secured to the other end of the lower gun shaft 82, and a similar crank and knuckle assembly 8| is secured to the adiacent end of the upper gun shaft 63, the assemblies 80 and 8l being threadedly connected to the connecting rod 82. Because the crank throw in each of the assemblies 11, 80, and 8| is variable, it is possible to adjust the amplitudes of oscillation of the gun shafts 62 and 63 independently of each other. This is a desirable feature since it is often advisable. for example. to have the upper guns 85 oscillate through a small angle while the lower guns oscillate through a wide angle. If. in adjusting the throw of the several crank arms to vary the amplitude of oscillation of the shafts, the gun shafts are twisted from their normal stationary position and the guns are no longer dlrected toward the ware at the proper angle, the gun shafts may be returned to their proper normal positions by lengthening or shortening the connecting rods 82 and 12 in the forked members in which the connecting rods are threadedly secured. l

The lower and upper guns 64 and 85 are supplied with the required atomizing and operating air from suitable compressors (not shown), through suitable exible tubing 84 and 85. Liquid glaze is supplied under pressure to the guns il and 85 through flexible tubing 86 and 81, respectively, from the centrifugal pump 58. The pump 88 is supplied with glaze from the glaze tank Il, which is preferably located under the booth drain 59 and is covered by the bouncing lawn 5|. The bouncing lawn 8| comprises a frame 92 over which is loosely stretched a fabric, preferably of finely woven lawn or muslin. Integral with the lawn frame l2 is a boss which is connected by a flexible shaft $4 toa sleeve Il secured to the end of the crank arm il of the crank and knuckle assembly 80. The flexible shaft 94 is substantially equal in length to the vertical distance between the boss 93 and the lower gun shaft l2. Thus,

' as the crank arm Si oscillates up and down from the normal position' shown in Figs. 4 and 5, the flexible connection 34 causes/the lawn 9i to be bounced, so that glaze poured upon the lawn Il will run through the e glaze straining fabric. Because glaze is rather viscous, the lawn 3l must be bounced" to prevent it from clogging, as it would do if it were merely vibrated.

Operation volved past the first spray guns, it is rotating at a fairly constant and, preferably, high rate of speed.

With a planetary motion imparted to the ware by the action of the revolving table l0 and rotating spindles 30. glaze is applied to the ware in a plurality of Asuccessive thin, substantially dry coats of glaze by the oscillating spray guns. As shownl in the drawings| the lower spray guns 64 first coat the lower and outer surfacesof the ware, and then the upper guns coat the inner and upper surfaces of the ware. It should be apparent, however.' that by reversing the direction of rotation of the table I0 or by simply turning the ware over on the holders 33 that the order. of coating the surfaces could be changed. It should also bev apparent that by merely mounting the upper gun` shafts above the lower gun shafts, that all surfaces of the ware' could be coated simultaneously.

Particular attention should be called to the fact that in the preferred operation of this apparatus, a plurality of successive thin and substantially dry coats of glaze are applied to the ware, thus preventing the glaze from running or curtaining." To perform this operation most successfully, the wetness of the glaze spray is regulated by adjusting the proportions of glaze and atomizing air in the spray. Thus, due to the action of the atomizing air upon the wet glaze, moisture vapor in the liquid glaze is evaporated and the glaze is comparatively dry when it contacts the ware. Because each coat is substantially dry when applied, there is less'tendency for the glaze to run than if it were applied in a liquid condition. Furthermore, the glaze is further dried and prevented from running because the more or less porous ware upon which it is applied absorbs the moisture content of the glaze. Therefore, in order to glaze a batch of ware, the glaze spray is adjusted so that it will not run when applied to the least absorptive .pieces in the batch. After the glaze sprays have been adjustedl for the least absorptive pieces of the batch of ware, the glaze,

of course, will not run when applied to the more absorptive pieces of ware in the batch.

vHaving in mind me feet niet the glaze applied.

to the ware should be dry enough to not run on the least absorptive ware, at the same time the glaze should be applied in e wet enough condi,-

tion toadhere to the ware. Since a thin coat of more or less wet glaze will not run while a thick coat of the same glaze would run, it is important. therefore, that in operating this apparatus in a manner to obtain best results, a plurality of thin coats be applied. This is achieved in the machine disclosed not only by oscillating the spray guns but by imparting planetary motion to thel spindles carrying the ware. Thus, each portion of the surface of the ware is sprayed a large number of times while being conveyed through the booth. The thinness of each coat results, of course, from the fact that each portion of the surface of the ware is subjected to the action of the sprays during each pass of the sprays for only a small instant of time. 'I'he preferred fiat fanlike jet `of spray from each gun also assists in ren. dering each coat of glaze thin.

In order to coat the glaze upon the ware properly, the glaze should be sprayer at a fairly wide angle to the surface oi' the ware. Therefore, in addition to achieving the application of a pluralvity of thin coats of glaze, the combined planetary movement of the ware and oscillatory movement of the fiat, fan-like sprays also causes the glaze to be applied to the ware at the proper angle.

Because the configuration of pieces of ware vary widely, not only should the gun shafts be adjustable independently of each other in regard to the angle through which the gun shafts oscillate, but each spray gun should be adjustable with respect toits supporting gun shaft, both as to the angle at which the spray is directed at the ware and as to the distance between the nozzle of the spray Bun and the ware. In the embodiment of this invention disclosed, such adjustments as to the distance between the nozzle of the spray guns and the ware may be made by sliding the rod 68 in the collar 6l; the angle at which the spray is directed at the ware may be adjusted by turning the collar 61 upon its supporting gun shaft, turning the rod 66 in collar 6l, and by pivoting the spray gun upon the bent stud portion of the rod 66 Thus, in order to be certain that each piece of ware may have glaze applied to all portions of its surface at a wide angle, where there are a plurality of guns on each gun shaft, some guns may be directed at an oblique or horizontal angle to coat vertical portions of the ware and other guns on the same shaft may be directed at a substan tially vertical angle to` coat horizontal portions of the ware.

In Fig. 4, both the lower and upper gun shafts 62 and 63 are shown as being oscillated through the same angle. As pointed out in the description of the gun shaft drive, however, each of the lower and upper gun shafts 62 and 63 may be regulated independently of each other as to the angle through which the gun shaft oscillates by adjusting the position of the knuckle member upon the crank arm in each of the knuckle and crank assemblies l1, 80, and 8l. An extreme example of the variation between the angles of oscillation of the lower and upper gun shafts is found in one manner of using this machine to glaze cups.v With cups placed upon the ware holders 33, the upper spray guns are adjusted so that they are located substantially above the center of the spindles 30 and are directed at a substantially vertical angle toward the ware, the vertical distance between the cups and the spray guns being sufficient to allow the divergence of the spray to include the diameter of the cup. The connecting rod 82 is then disconnected so that the upper gun shaft :incassi II does not oscillatebt all while the lower gun shaft 62 oscillates through an-,anglc sumcient to walls and handles of the cups. The inside walls and bottoms of the cups are coated by simply ro- During the normal operation of the machine the spray guns are operating constantly. Considerable quantities of glaze, therefore. may not be applied to the ware but tend to collect upon the floor Bl of the booth 50. Such excess glaze flows from the booth over the surface Ii of the table i and most of it runs over the depending eave I6 into the trough 80. Glaze which is carried outside the booth 50 on the revolving table ill falls into the circular trough l1 and thence iiows into the .I allow the lower spray guns to coat the outside v said guns and accumulated in said booth, and

means to supply said recovered glaze to said guns.

2. In a machine for applying Lglaze to ceramic ware, a revolving table, a plurality of spindles carried by said table, a spray booth located over a portion'o! said table and adapted to permit the revolution oi' said table therethrough. means for rotating said spindles while said spindles revolve through said booth on said table, spray guns' mounted -for continuous oscillation on said booth,

means operating independently of the revolution trough 60. Thus, excess glaze is returned from the trough 80 to the bouncing lawn 8i by the trough drains 59. Glaze which passes the bouncing lawn 9i falls into the glaze reservoir 90 whence it is returned to the spray guns by the pump v8! through the flexible tubing 86 and 81.

The flexible connection 94 not only fbounces the lawn 9| so that it -does not clog, but because of its iexibility, it causes the lawn 9i to "bounce" at a higher frequency than the frequency of oscillation of the crank arm 95. It should be noted here that if the motor 1i! is connected to the upper gun shaft 63, instead of the lower gu'n shaft B2, as in the present instance, the iiexible connection $4 may extend from the boss 93 to the knuckle and crank assembly 8i and its length should be substantially equal to the vertical distance from the boss 93 to the upper gun shaft 83.

Coated ware is removed from the ware holders 33 after the spindles ceased rotation caused by the belt 45. In a circular machine as disclosed,

the unloading station is most conveniently located adjacent the loading station, i. e., near the entrance of the booth 50 in order to give the glaze on the ware the maximum time for drying, although, since the glaze is applied in a relatively dry condition, the ware may be handled safely shortly after it leaves the booth 50.

From the foregoing it should be apparent that this invention is not limited to the particular embodiment disclosed, either in whole or in part, but is limited only by the appended claims.

I What is claimed is:

1. In a machine Ifor applying glaze to ceramic ware, a table. means for revolving said table, a plurality of spindles adapted to support ceramic ware carried by said table, pulleys on said spindles, a spray booth extending over a portion of said table and adapted to permit the revolution therethrough of said table, spindles, and ware supported by said spindle, means adapted to engage said pulleys frictionally to rotate said spindles revolved through said booth, spray guns mounted for continuous oscillation on said booth and directed toward ware carried by said spindles, means independent of the means for revolving said table for oscillating said spray guns with respect to said ware to cover all surfaces of said ware. means to recover excess glaze sprayed by oi' said table for oscillating said spray guns with respect to ware carried by said spindles, and means for recirculating excess glaze sprayed by said guns to said guns.

3. In a machine for applying glaze to ceramic` ware, a revolving table, a plurality of spindles adapted to support ceramic ware carried by said table, a pulley secured to each of said spindles, a spray booth extending overa portion of said table and adapted to permit the passage of said table, spindles, and'ware `supported by said spindles therethrough, a frictional lmember supported under saldtable beneath said spray booth, said frictional member engaging said pulleys secured to said spindles to rotate said spindles while said spindles are revolved through said booth on said table, spray guns mounted for continuous oscil- .glaze all surfaces of ware supported on said rotating spindles, means to oscillate said spray guns independently of the movement of said spindles.

4. In a 'machine for applying glaze to ceramic ware, a revolving table, a plurality of spindles adapted to support'ceramic ware carried by said table, a pulley secured to each of said spindles, a spray boothextending over a portion of said table and adapted to permit the passage of said table, spindles, and ware supported by said spin dles therethrough, a v-belt supported under said table beneath said spray booth, said V-.belt engaging said pulleys on said spindles, variable drive means for said V-belt to impart planetary motion to spindles, oscillating spray guns mounted for continuous. oscillation on said booth to coat all surfaces of ware carried by said spindles during the planetary movement thereof, and means to oscillate said spray guns independently of the movement of said spindles.

5. In a machine for applying glaze to ceramic ware, a revolving table having a sloping surface,

` a plurality o! spindles adapted to support ceramic ware carried by said table, means to impart planetary motion to said spindles through a portion of the orbit thereof, a spray booth located over said table adjacent the portion of the table at which planetary motion is imparted to said spindles, va

floor and a.K ceiling in said booth, spray gunsv cillate said spray guns independently oi the planetary motion of said spindles, a glaze reservoir, the oor of said booth being designed to direct excess glaze sprayed by said guns and accumulated on said floor over said table to said glaze reservoir, and the ceiling of said booth being slanted over said spindles to prevent excess glaze spray accumulated thereon from dripping on ware supported by said spindles.

6. In a machine for applying glaze to ceramic ware, a revolving table having a sloping surface, a plurality of spindles adapted to support ceramic ware carried by said table, means to impart planetary motion to said spindles through a Prtion of the orbit thereof, a spray booth located over said table adjacent the portion of the table at which planetary motion is imparted to said spindles. a sloping floor in said booth, said floor being lo cated above said table and having its lower edge terminating above said sloping table surface adjacent the orbit of said spindles, spray guns mounted on said booth to spray glaze upon ware supported by said spindles, a trough in said booth below said table, and a circular gutter beneath the periphery of said table outside said booth, whereby, due to the slope of said floor and the slope of said table surface, excess glaze sprayed by said guns and accumulating on said floor will drain off said floor and over said table into said trough, excess glaze carried out of said booth by said revolving table being received in said gutter and draining into said trough.

7. In a machine for applying glaze to ceramic ware, a revolving table, spindles carried by said to permit said table and spindles to revolve therethrough, means for rotating said spindles within said booth, a first gun shaft mounted on said booth, a second gun shaft mounted on said booth, a plurality of spray guns mounted on each of said shafts, said spray guns being directed toward ware supported by said spindles, a gun shaft driving motor, a first connectingY means from said motor to said first gun shaft, and a second connecting means from said first gun shaft to said second gun shaft, said first and second connecting means permitting said gun shafts to be oscillated through diderent angles of oscillation.

8. In a machine for applying glaze to ceramic ware, a revolving table, spindles carried by said table for supporting ceramic ware, a spray booth extending over a portion of said table and adapted to permit said table and spindles to revolve therethrough, means for rotating said spindles within said booth. a first gun shaft mounted on said booth. a second gun shaft mounted on said booth. a plurality of spray guns mounted ori/each of said shafts, said spray guns being directed toward ware supported by said spindles. a gun shaft driving motor. a nrst crank arm and knuckle assembly on said ilrst gun shaft, a first connecting rod between said motor and said first crank arm and knuckle assembly, a second crank arm on said ilrst gun shaft. a third crank arm and knuckle assembly on said second gun shaft, a second connecting rod between said second and third crank arm and knuckle assemblies, each of said crank extending over a portion of said table and adapted to permit said table and spindles to revolve therethrough, means for rotating said spindles within said booth, a ilrst gun shaft mounted on said booth. a second gun shaft mounted on said booth. a plurality of spray guns mounted on each of said shafts. said spray guns being directed toward ware supported by said spindles. a gun shaft driving motor. a nrst crank arm and knuckle assembly on said first gun shaft, a first connecting rod between said motor and said rst crank i 10 arm and knuckle assembly, a second crank arm on said first gun shaft, a third crank arm and knuckle assembly on said second gun shaft, a second connecting rod between said second and third crank arm and knuckle assemblies, each of said crank arm and knuckle assemblies being adjustable to oscillate said gun shafts through different angles of oscillation," each of said crank arm and knuckle assemblies comprising a crank arm disposed at substantially right angles to a gun shaft and a knuckle member adjustably secured to said crank arm to vary the radial disilzaance vfrom said gun shaft to said knuckle mem- 10. In a machine of the class described, a revolving table, rotatable spindles on said table, a booth extending over a portion of said table and adapted to permit said table and spindles to revolve therethrough, spray guns mounted for continuous oscillation on said booth and adapted to spray glaze on ware supported by said spindles.

means to oscillate said spray guns independently of the movement of said spindles, a glaze reservoir. a lawn over said reservoir, an oscillating shaft, a flexible connection from said lawn to said shaft substantially equal to the distance between said lawn and said shaft, said flexible connection being adapted to bounce said lawn^"oei"said reservoir at a frequency higher than the frequency of oscillation of said shaft.

11. Apparatus as defined in claim 7 including means for disconnecting a portion of said spray means from said oscillating means.

12. Apparatus as defined in claim 2 in which said spray guns spray a flat spray of atomized glaze and air, and means to adjust the proportion of glaze and air sprayed by said spray guns.

13. A machine for applying glaze to ceramic ware as deilned in claim 2, in which said spray guns are adapted to spray the glaze in thin, substantially dry coats of glaze upon the ware carried by the spindles.

HOWARD V. SCHWEITZER.

REFERENCES CITED The following references are of record in the` ille of this patent:

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